| Johnius belangerii and Dendrophysa russelli are all affiliated with perciformes, basssuborder, drum fish; they are live in bottom of the warm water and close the shore.Through the investigation from2008to2009, we found Johnius belangerii andDendrophysa russelli are taken dominant position in local area of Liusha Bay.This paperwill study two kinds of drum fish in the field of biology, breeding, feeding habits andnutrients, in order to lay a foundation for develop and utilize two fish. The main results ofthis paper are as follows:Johnius belangerii’s weight grows faster than the length, Dendrophysa russelli’sweight grows more slowly than the length, Johnius belangerii has a dominant body lengthin12.1～14.0cm, Dendrophysa russelli has a dominant body length in11.6～12.5cm. Thenutritional statuses of two fish are batter in front of breeding season than after, thenutritional statuses are best in the fall.The average egg size of Johnius belangerii and Dendrophysa russelli was0.470mmand0.381mm respectively, Absolute fecundity ranged from20672to60717and21289to52151respectively, the fecundity of Johnius belangerii was related to length and weight,however, the fecundity of Dendrophysa russelli was not so closely related to lengthandweight, Two species of female fish annual GSI index was highest in March, lowest inJanuary, and it has Significant negative correlations between GSI index and HSI index, thecorrelation coefficient was-0.4340and-0.4765respectively. Two species of male fishannual GSI index was highest in April. Tissue histologic showed that two kinds of fishovarian development was very similar to general teleost fishes, it can be divided into6periods. Analysis showd that the spawning period of Johnius belangerii was March toOctober, the reproductive peak in March, and the spawning period of Dendrophysa russelliwas in March to September, the reproductive peak in March to May, two kinds ofdrum fish were batch spawning, egg cells in ovary development was not synchronized; theovarian development temperature of two type of drum fish was21～31℃, spawningtemperature was25～31℃, the optimum reproductive temperature was25～29℃.Crustaceans and young fish are major foods of two rum fish; they take a proportionof weight in all foods was95.68%of Johnius belangerii, and take81.46%in Dendrophysarusselli. Dendrophysa russelli feeding more types of foods than Johnius belangerii, thecapacity of feeding in two fish have significant seasonal variation, autumn> summer> spring> winter. We calculated out the trophic level of Johnius belangerii was3.10, and thetrophic level of Dendrophysa russelli was2.87, therefore we infer that there is competitionto some extent for food between two kinds of drum fish in the area of Liusha Bay.The stable15N‰ratios ranged of Johnius belangerii from13.99‰～15.04‰,trophic level ranged from2.72to3.36. The stable15N‰ratios ranged of Dendrophysarusselli from13.99‰～15.04‰, trophic level ranged from2.69to3.11. The results showthat two difference Drum fish are in the same trophic level, they all belong to intermediatecarnivorous fishes.According to the theory of hybrid models, we calculate the averagevalue of index of diet overlap was88.62%, thismeans that there is competition for foodbetween two kinds of drum fish in the area of Liusha Bay.The crude fat content in muscle of johnius belangeri and Dendrophysa russelli was7.19%and5.68%respectively, the crude protein content was16.92%and16.47%respectively, crude ash content was1.35%and1.11%respectively; moisture content was76.41%and78.13%respectively. Johnius belangeri and Dendrophysa russelli contain17kinds of amino acids, and essential amino acid content was24.53%and26.35%of totalamino acids. It detected21and23species of fatty acids in the muscles of their back,unsaturated fatty acids accounting for49.33%and46.83%respectively; the sum of EPAand DHA was13.83%and11.09%respectively. Heavy metal test show that heavy metalcontent in the fishes stay in safe range. According to AAS, CS evaluation andcomprehensive analysis, muscle protein nutritional value of johnius belangeri was lessthan Dendrophysa russelli. The fatty acids nutritional value of johnius belangeri was morethan value of Dendrophysa russelli. In comprehension, two stone have a good taste andhigh nutritional value, and there are a certain potential for development. |
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